Extremist Muslim groups are active on university campuses throughout Britain, according to a new report.

More than 30 places of higher education are named in the study by Anthony Glees, director of Brunel University’s Centre for Intelligence and Security Studies, as having been infiltrated by “extremist and/or terror groups.” Radical groups Hizb ut-Tahrir and al-Muhajiroun, banned from university campuses because of their extremism and anti-Semitism, were found still to be operating under different names.

The report also detailed far-right and animal-rights groups. “This is a serious threat,” Glees told the Guardian newspaper. “We have discovered a number of universities where subversive activities are taking place, often without the knowledge of the university authorities.”